Increased knowledge of vascular function during chronic gingival inflammation is likely to add to the knowledge of the nature of the disease process and of the prognosis for tissue recovery. Although morphological changes in regular vascular networks to a "looped" arrangement have been demonstrated in free gingiva early in the course of chronic gingivitis, the extent to which changes in vascular function accompany these changes in vascular morphology is not known. The objectives of this research are to investigate selected aspects of vascular function in young and adult non inflamed and inflamed gingiva of dogs. Blood flow rate and volume for total gingiva will be measured using radio-isotope labelling techniques. Vascular surface area and capillary structure in selected gingival sites will be measured using light and electron microscopy and image analysis techniques.